The Lady of Luminosity American Astronomer of the First Magnitude
Henrietta Swan By: Saia Patel May 2016 Leavitt Science
(1868—1921) Henrietta Swan Leavitt Early Life
❖ born on July 4, 1868 in Lancaster, MA
❖ attended Oberlin College, graduated from the Society for the Collegiate Instruction for Women (Radcliffe College) in 1892
❖ traveled in America and Europe where she lost her hearing
❖ became volunteer research assistant at Harvard College Observatory
❖ interest in astronomy began during senior year of college: took astronomy class
❖ given position of chief of the photographic photometry department, responsible for the care of telescopes
Some Important Terms to Know…
❖ Variable Stars—a star whose brightness as seen from Earth (its apparent magnitude) fluctuates
❖ Cepheid Variable—intrinsic variable stars which pulsate in a predicatable way
❖ Fluctuation—to rise and fall irregularly in number or amount
❖ Intrinsic Brightness—how bright the stars would be at a common distance
❖ Magellanic Cloud—two irregular dwarf galaxies orbiting the Milky Way Galaxy
Harvard College Observatory
❖ liked astronomy so much that she became a volunteer at the Harvard College Observatory as a "computer"
❖ "the Harvard computers"—the name used for women who examined tiny dots on time–exposed photographs of night sky and then measured, calculated, and recorded their observations in ledger books
❖ in 1902, she was hired at 30¢ per hour and worked there for 19 years until her death
Leavitt's Law
❖ discovered a direct correlation between the time that it takes for Cepheid variable to go from bright to dim and back, and the brightness of the star
❖ the longer the period of fluctuation, the brighter the star
❖ that means that even though that a star might seem dim, if it had a long period, it must be large
❖ calculated how bright the star appeared from Earth, and compared it to its intrinsic brightness
❖ could estimate how much of the star's brightness had faded away while reaching Earth, and the distance of the star “A straight line can readily be drawn among each of the two series of points corresponding to maxima and minima, thus showing that there is a simple relation between the brightness of the variables and their periods.”
–Henrietta Swan Leavitt Commenting on her discovery The End of her Life
❖ worked irregularly at Harvard due to health problems and family obligations
❖ made head of stellar photometry in 1921 by new director, Harlow Shapley
❖ passed away from cancer in 1921
❖ unaware of death, Gosta mittag Leffler, a Swedish Mathematician considered nominating her for the 1926 Nobel Prize in Physics and wrote to Shapley for more information
❖ Shapely responded and said Leavitt was dead, but he should consider nominating him because he "correctly interpreted" Leavitt's discovery
❖ Nobel Prize not awarded posthumously
❖ asteroid 5383 Leavitt and lunar crater Leavitt named in her honor
Effects of her Work
❖ Ejnar Hertzsprung, Danish astronomer and chemist, used her discoveries to plot the distance of stars
❖ Harlow Shapley, American astronomer, used her discovery to measure the size of the Milky Way
❖ Edwin Hubble, American astronomer and the creator of Hubble Telescope, used her discovery to discover the age of Universe Accomplishments
❖ American astronomer of the first magnitude
❖ her research resulted in advances within the field of astronomy
❖ discovered how to rank stars's magnitudes using photographic plates
❖ discovered a way to accurately measure extra galactic distances (period-luminosity relation)
❖ discovered more variable stars than any other astronomer in her time
❖ asteroid 5383 Leavitt and lunar crater Leavitt named after her and deaf astronomers and scientists
❖ member of Phi Beta Kappa, the American Association of University Women, the American Astronomical and Astrophysical Society, the American Association for the Advancement of Science, and an honorary member of the American Association of Variable Star Observers Biographic Books and Plays
❖ Silent Sky, a play written by Lauren Gunderson follows Henrietta's journey in life
❖ Miss Leavitt's Stars, a biography written by George Johnson tells the triumphs of women's progress in science through Henrietta Leavitt's life
And Many More…
Other Events During Leavitt's Life 1914–World War I begins 1869–Mendeleev makes periodic 1916–Einstein publishes table General Theory of 1882–Charles Darwin dies Relativity
1889–Van Gogh paints Starry Night 1920–Women 1876–Telephone given right to patented vote in U.S. 1898–Curie discovers radium and polonium
1870 1880 1890 1900 1910 1920
1885–1888–Attends Oberlin College 1893–1902– Volunteer Work at Harvard College 1908–Publishes theory Observatory 1888–1892–Attends 1921–Dies of cancer 1902–1921–Paid work at Radcliffe College Observatory, loses hearing 1868–Born on July 4 in 1902–1908–Discovers Cepheid variable stars Lancaster, MA and develops period–luminosity theory
Leavitt's Life Sources
❖ https://en.m.wikipedia.org/wiki/Henrietta_Swan_Leavitt
❖ http://www.pbs.org/wgbh/aso/databank/entries/ baleav.html
❖ http://www.sheisanastronomer.org/index.php/history/ henrietta-leavitt
❖ https://www.slideshare.net/mobile/BigHistory/u2-bioleavitt
❖ https://prezi.com/m/-ilsk4su79z6/henrietta-swan-leavitt/
❖ https://prezi.com/m/znf_fuqydi8_/henrietta-leavitt/ The End